[llvm] Fix compress/decompress in LLVM Offloading API (PR #150064)

[Joseph Huber via llvm-commits]

================
@@ -260,11 +299,233 @@ static std::string formatWithCommas(unsigned long long Value) {
 }
 
 llvm::Expected<std::unique_ptr<llvm::MemoryBuffer>>
-CompressedOffloadBundle::decompress(llvm::MemoryBufferRef &Input,
+CompressedOffloadBundle::compress(llvm::compression::Params P,
+                                  const llvm::MemoryBuffer &Input,
+                                  uint16_t Version, bool Verbose) {
+  if (!llvm::compression::zstd::isAvailable() &&
+      !llvm::compression::zlib::isAvailable())
+    return createStringError(llvm::inconvertibleErrorCode(),
----------------
jhuber6 wrote:

```suggestion
    return createStringError(
```
Pretty sure there's a constructor that does the error code for you.

https://github.com/llvm/llvm-project/pull/150064